Mechanically operated fuse for gyratory missiles

ABSTRACT

A fuse provided with safety means operative before firing and during the beginning of the flight of the missile, said fuse including an escapement controlling a toothed sector which is adapted after a lapse of time defined by the escapement to shift a primer carrier into an intermediate position for which centrifugal force urges said carrier into its operative position corresponding to alignment of the actual primer between the striker and the detonator.

United States Patent Simmen May 13, 1 975 [54] MECHANICALLY OPERATED FUSE FOR 3,039,392 6/1962 Simmen 102/79 ILES 3,334,589 8/1967 102/79 GYRATORY MISS 3,347,166 10/1967 102/71 X [75] Inventor: Robert Sim e e a, 3,583,319 6/1971 James 162/79 Switzerland v 1 [73] Assignee: Metina S.A., Fribourg, Switzerland Primary Examiner-Robert F. Stahl F E Filed: Sept. 26,1972 Attorney, Agent or zrm mory L Groff Jr [21] Appl. No.: 292,293 [57] ABSTRACT A fuse provided with safety means operative before [30] Forelgn Apphfatlon Pnonty Data firing and during the beginning of the flight of the mis- OCI. ii, 197] Switzerland [4791/71 i Said fuse including an escapement controlling a toothed sector which is adapted after a lapse of time U-S. defined the escapement to shift a primer carrier 1]!- CL i an intermediate position for centrifugal [58] held of Search 102/71 80 force urges said carrier into its operative position corresponding to alignment of the actual primer between [56] References cue! the striker and the detonator.

UNITED STATES PATENTS 2,718,850 9/1955 Kuhn 102/79 6 Clams 7 Draw guns l V I) PATENTEU MAY 1 319. 5 33823.82

sum 2 or 4 PATENIED RAY I 31975 SHEEI 3 BF 4 PATENTEI] RAY I 31975 SHEET Q 0F 4 MECHANICALLY OPERATED FUSE FOR GYRATORY MISSILES The present invention has for its object a fuse adapted to equip missiles assuming, after the shot has been fired, a gyratory movement around their axis.

It relates more particularly, inter alia, to a fuse for small gauge missiles.

Generally, it is required that such a fuse should not only incorporate means providing explosion upon impact on the target and self-destroying means destroying the missile if it misses the target, but should also be provided with means ensuring safety during storage, that is safety for the detonator and above all with means extending over a sufficient time of flight, so as to render the fuse inoperative even if after the firing of the shot, the missile impinges against an object at say 50 or 100 m beyond the muzzle of the gun. This safety feature during the path of travel of the missile is of particular interest in the case of fuses on missiles fired from an aircraft.

Fuses are known which include means, ensuring safety during flight, comprising a metal strip wound around the striker and locking it in its inoperative position corresponding to its storing position before firing. When the shot has been fired, the strip unwinds under the action of the rotary movement assumed by the missile and releases the striker after a short lapse of time. The safety during flight thus obtained is satisfactory only when the fuse impinges on a target of a low density. If such a fuse impinges, immediately after it has left the gun muzzle, against a solid object, the front of the fuse is crushed thereby and the striker may, in spite of the presence of the metal strip, hit the primer and ignite it.

Furthermore, the unwinding of the metal strip provides the fuse with a safety during flight which is clearly less than that which may be expected from a modern fuse.

Other known fuses include, in addition to the metal strip referred to, a rotary member enclosing a detonat ing primer. Such an arrangement provides the fuse with safety means during storing periods, since said rotary member is, before the firing of the missile, in a sloping position, such that no transmission of the ignition can be transmitted through the detonating primer to the actual detonator.

When the shot has been fired and the missile has actually left the gun muzzle, the rotary member passes out of its sloping position into an axial position under the action of the rotary movement of the missile, so that the detonating primer is now alined with the striker and can be ignited by the latter as soon as the fuse hits a solid object. This arrangement again brings no improvement as concerns safety during flight.

Other known fuse structures are not provided with a metal strip and with a rotary member, but witha mechanical safety system. The latter includes chiefly a pivoting or sliding member which, when in its storing condition, shifts the primer it carries out of the way of the striker. When the shot has been fired, said pivoting or sliding member pushes gradually the primer into a position underneath the striker at a speed which is slowed down by a clockwork mechanism. Since the room available is very restricted in a small gauge fuse, the manufacturer is practically incapable of ensuring through such means an adequate safety arrangement over a sufficiently long flight while keeping within an allowable cost price for the fuse.

The present invention has for its object to remove the above-mentioned drawbacks and to produce a safe and reliable fuse which is also simple to manufacture.

The invention has for its object an instantaneously mechanically operating fuse with safety means for the detonator and during the beginning of the flight, said fuse being of the type to be fitted on gyratory missiles and including a body, a striker, a pivoting primercarrier adapted to be shifted from a safety position into a missile-firing position against the action of a return spring, as provided by the centrifugal force produced by the rotation of the missile, and an escapement defining the time required for said shifting of the primercarrier. The novelty of the invention resides in the fact that the centre of gravity of the primer-carrier is lo= cated in the vicinity of, but outside of a straight line.

of the shot, so as to act on the primer-carrier and to urge it into a position for which its centre of gravity lies on the opposite side of the above-mentioned line.

The accompanying drawing illustrates, by way of ex-.

ample, an a preferred embodiment of such an improved fuse. In said drawing:

FIG. 1 is a longitudinal sectional view of a fuse made in accordance with the invention and shows the opera tive parts of the fuse in the position occupied by them before the starting of the shot.

FIG. 2 is a longitudinal cross-section through line II--II of FIG. 3 of the safety means when in their inoperative condition prior to the starting of the shot.

FIG. 3 is a transverse cross-section of said safety means through line IlI-III of FIG. 2.

FIG. 4 is a further transverse cross-section of .said safety means through line IVIV of FIG. 2.

FIG. 5 is a cross-section similar to FIG. 3, showing however the operative parts in the position occupied by them at the moment at which the primer-carrier is shifted towards its operative cocked position by the released movable member controlled by the escapement.

FIG. 6 is a cross-section similar to FIG. 2, showing the safety means in their cocked position.

FIG. 7 is a transverse cross-section through line VI-VI of FIG. 6.

The fuse illustrated includes a body 1, the upper section of which is closed by a disc 2. The body 1 encloses a safety and self-destroying system well-known per se and comprising a socket 3, transversely sliding members 4, a spring 5 surrounding the latter, balls or the like weights 7, a carrier for said weights and a fusedestroying spring 8.

The striker mechanism is constituted by a striker 9 and by its head 10. The body 1 enclosed furthermore the auxiliary safety mechanism 11 with its detonating primer 12. The lower section of the body 1 is closed by a plug 13 inside which is fitted the detonator 14.

The auxiliary safety means 11 are fitted inside the body 1 between the transverse plates 15; 16 and 17 which are interconnected by rivets or studs 18, 19 and 20 (FIG. 3). A pivot member 21 fitted between the plates 16 and 17 carries the revolvable primer-carrier 22 and the revolvable movable sector-shaped member 23 controlled by the escapement and adapted to shift said primer-carrier. The latter is provided with an upwardly directed projection 24 engaging through its upper end an arcuate slot 25 in the movable driving sector-shaped member 23. The actual primer 12 is housed within a bore of the primer-carrier 22 and is subjected to a thrust exerted downwardly on it by the spring 12a (.FIG. 1).

The driving sector-shaped member 23 has its centre of gravity at 26 and it is provided with an arcuate toothed periphery 27 coaxial with the pivot 21 meshing with a pinion 28 forming part of the escapement 29. As illustrated in FIG. 4, said escapement includes an escape wheel 30 revolving in unison with said pinion 28 and cooperating with the pallet 31 pivotally secured to the tube 32 through which the striker 9 extends. The sector-shaped member 23 is held fast before firing, in the position illustrated in FIG. 3, by a spring 33. The primer-carrier 22, the centre of gravity of which is shown at 34, is held in the position illustrated in FIG. 3 by the same spring 33 through the agency of the sector-shaped member 23, the arcuate slot 25 of which engages through its end the projection 24 on the member 23. Thus, the primer-carrier 22 is urged against the rivet or stud 18 which plays the part of a stop.

The operation of the fuse is as follows.

When the shot has been fired and the missile is beyond the gun muzzle, the fuse is no longer subjected to an axial acceleration and revolves with the missile, so that the sliding members 4 move radially apart and thereby shift upwardly the weight carrier 6, and simultaneously release the striker 9. The weight-carrier 6 then continues its forward movement against the action of the fuse destroying spring 8 because the weights 7 are shifted by centrifugal force along the upwardly flaring frustoconical surface 36 of the socket 3.

While said weights are urged outwardly by centrifugal force, the sector shaped member 23 having its centre of gravity at 26 rocks around its pivot 21 member also under the action of centrifugal force and drives the pinion 28 together with the escape wheel 30. The rotary movement of the escape wheel and, consequently, also the sector shaped member 23 are controlled and slowed down by the oscillations of the pallet 31.

The primer-carrier 22, the centre of gravity of which is shown at 34, remains locked in its storing position by centrifugal force.

When the sector shaped member 23 has reached the outward position illustrated in FIG. 5, it engages the projection 24 through the rear end of its slot 25. Thereby it draws along with it the primer-carrier and makes it enter its operative cocked position; the sector shaped member 23, being then released from its engagement with the pinion 21, is no longer slowed down by the escape wheel and suddenly enters its outermost position illustrated in FIG. 6, in which it engages the inner wall 35 of the body 1.

When this outermost position of the sector shaped member 23 is reached, the primer-carrier 22 has been caused to rock so that its centre of gravity 34 has been moved to the opposite side of the straight line connecting its pivotal axis 21 with the rotary axis of the fuse. The primer-carrier 22 then continues its pivotal movement under the action of centrifugal force until the detonating primer 12 registers with the axis of the striker 9 as illustrated in FIG. 7. The primer is then urged by its spring 12a through an opening 36' in the transverse plate 17, whereby the primer-carrier 22 is locked in its cocked position.

From this moment on, the fuse is cocked and ready to operate. If it impinges against the target, the tip of the fuse is crushed and the striker 9 is hit by its head 10 so as to enter the detonating primer 12. The latter causes then the detonator 14, and'consequently, the missile to explode.

If, in contradistinction, the fuse misses the target, its self-destruction occurs after a predetermined lapse of time. As a matter of fact, the rotary speed of the missile and consequently the centrifugal force decrease during flight. As soon as the component of centrifugal force holding the weight carrier in its raised position drops below the value of the thrust exerted by selfdestruction spring 8, the weights 7 move downwardly over the frustoconical surface of the socket 3, so that the weight carrier drives the striker 9 into the detonating primer 12.

Since the primer-carrier 22 can enter the position into which it is urged centrifugally only when the sector shaped member 23 has travelled over the path described, a safety condition is obtained over a large fraction of the flight of the missile. This safety condition could in fact be easily extended over a longer period by providing a toothed peripheral sector on the actual primer-carrier 22, which sector would then mesh with the pinion 28 assumed to extend axially by a sufficient length. The escapement would thus serve a dual purpose, that of controlling first the pivotal motion of the sector shaped member 23 and then that of the primercarrier 22.

I claim:

1. A fuse for a gyratory missile comprising inside of a hollow body a detonator (14), a striker (9) adapted to move axially of the fuse towards said detonator, a primer-carrier (22), a pivot member (21) whose axis is located parallel with the path of movement of a striker and on which said primer-carrier (22) is pivotally mounted, said primer-carrier (22) movable out of an inoperative position and into an operative position under the action of centrifugal force, the center of gravity (34) of said primer-carrier (22) when inoperative, lying on the side of a straight line connecting the axis of rotation of the fuse with the pivot member (21) of the primer-carrier (22), the effect of centrifugal force tending to maintain the primer-carrier (22) in inoperative position, a primer (12) extending through said carrier along a line parallel with said primercarrier axis and assuming an operative position between the striker (9) and the detonator (14) when the primer-carrier (22) assumes its operative position, a spring (33) releasably holding the primer-carrier in its inoperative position, a movable member (23) mounted on said primer-carrier pivot member above said primer-carrier (22) and in engagement therewith, said movable member (23) being shiftable centrifugally to thereby cause the primer-carrier (22) to enter a position for which the center of gravity thereof lies on the other side of said straight line and the primer-carrier is urged by centrifugal force into its operative position, and an escapement mechanism (29) cooperating with said movable member (23) to slow down its movement towards its centrifugally instigated position.

2. A fuse as claimed in claim 1, wherein the movable member comprises a sector shaped member and said fuse includes elastic means holding said sector shaped member against motion until centrifugal force starts acting.

3. A fuse as claimed in claim 1, wherein the movable member engages the primer-carrier through a connection providing an idle motion at the start and comprising a projection carried by one of said parts, said projection engaging a slot in the other part.

4. A fuse as claimed in claim 1, wherein the movable member is provided with a peripheral series of teeth distributed along a circle coaxial with the axis of said member and the escapement mechanism includes an escape wheel and a pinion coaxially rigid with said wheel and meshing with said series of teeth to slow down the movement of the movable member.

5. A fuse as claimed in claim 1, wherein the movable member is provided with a peripheral series of teeth distributed along a circle coaxial with the axis of said member and the escapement mechanism includes an escape wheel and a pinion coaxially rigid with said wheel and meshing with said series of teeth to slow down the movement of the movable member, the primer-carrier being also provided with a peripheral series of teeth distributed along a circle coaxial with the axis of said carrierand meshing with said pinion to slow down the movement of the carrier.

6. A fuse as claimed in claim I, wherein the movable member is adapted to pivot centrifugally around the pivot member of the primer-carrier in superposed relationship with the latter and held against motion by said spring until centrifugal force starts acting, said movable member being provided with an arcuate slot concentric with its pivotal axis and with a series of teeth extending over a limited arc concentric with said axis, said escapement including an escape wheel and a pinion interconnecting said escape wheel with said teeth to slow down the movement of the movable member and said primer-carrier is rigid with a projection engaging the arcuate slot, whereby the slot in the movable member moves first under the action of centrifugal force over i said projection at a speed controlled by the pinion conber urges the primer-carrier into its operative position. 

1. A fuse for a gyratory missile comprising inside of a hollow body a detonator (14), a striker (9) adapted to move axially of the fuse towards said detonator, a primer-carrier (22), a pivot member (21) whose axis is located parallel with the path of movement of a striker and on which said primer-carrier (22) is pivotally mounted, said primer-carrier (22) movable out of an inoperative position and into an operative position under the action of centrifugal force, the center of gravity (34) of said primer-carrier (22) when inoperative, lying on the side of a straight line connecting the axis of rotation of the fuse with the pivot member (21) of the primer-carrier (22), the effect of centrifugal force tending to maintain the primer-carrier (22) in inoperative position, a primer (12) extending through said carrier along a line parallel with said primer-carrier axis and assuming an operative position between the striker (9) and the detonator (14) when the primer-carrier (22) assumes its operative position, a spring (33) releasably holding the primer-carrier in its inoperative position, a movable member (23) mounted on said primer-carrier pivot member above said primer-carrier (22) and in engagement therewith, said movable member (23) being shiftable centrifugally to thereby cause the primer-carrier (22) to enter a position for which the center of gravity thereof lies on the other side of said straight line and the primer-carrier is urged by centrifugal force into its operative position, and an escapement mechanism (29) cooperating with said movable member (23) to slow down its movement towards its centrifugally instigated position.
 2. A fuse as claimed in claim 1, wherein the movable member comprises a sector shaped member and said fuse includes elastic means holding said sector shaped member against motion until centrifugal force starts acting.
 3. A fuse as claimed in claim 1, wherein the movable member engages the primer-carrier through a connection providing an idle motion at the start and comprising a projection carried by one of said parts, said projection engaging a slot in the other part.
 4. A fuse as claimed in claim 1, wherein the movable member is provided with a peripheral series of teeth distributed along a circle coaxial with the axis of said member and the escapement mechanism includes an escape wheel and a pinion coaxially rigid with said wheel and meshing with said series of teeth to slow down the movement of the movable member.
 5. A fuse as claimed in claim 1, wherein the movable member is provided with a peripheral series of teeth distributed along a circle coaxial with the axis of said member and the escapement mechanism includes an escape wheel and a pinion coaxially rigid with said wheel and meshing with said series of teeth to slow down the movement of the movable member, the primer-carrier being also provided with a peripheral series of teeth distributed along a circle coaxial with the axis of said carrier and meshing with said piniOn to slow down the movement of the carrier.
 6. A fuse as claimed in claim 1, wherein the movable member is adapted to pivot centrifugally around the pivot member of the primer-carrier in superposed relationship with the latter and held against motion by said spring until centrifugal force starts acting, said movable member being provided with an arcuate slot concentric with its pivotal axis and with a series of teeth extending over a limited arc concentric with said axis, said escapement including an escape wheel and a pinion interconnecting said escape wheel with said teeth to slow down the movement of the movable member and said primer-carrier is rigid with a projection engaging the arcuate slot, whereby the slot in the movable member moves first under the action of centrifugal force over said projection at a speed controlled by the pinion connected with the escape wheel, following which the teeth disengage the pinion and the thus released member urges the primer-carrier into its operative position. 